Measurements & Units Flashcards
What are some instruments used to measure length, area, and volume?
Instruments include the metre rule, vernier calipers, micrometer screw gauge, and measuring cylinder.
What is the unit of mass?
The unit of mass is the kilogram (kg).
How do you measure the volume of an irregular object?
You can measure the volume of an irregular object by using a measuring cylinder and observing the displacement of water.
What is the unit of time?
The unit of time is the second (s).
What instrument is commonly used to measure mass?
A simple beam balance, such as Buchart’s balance or a chemical balance, is used to measure mass.
How does a beam balance work?
A beam balance measures mass by comparing the object’s weight to known masses on opposite sides of a horizontal beam.
What devices are used to measure time?
Time-measuring devices include stopwatches, clocks, and timers.
What are fundamental physical quantities?
Fundamental physical quantities include length, mass, and time, each with corresponding units like meters (m), kilograms (kg), and seconds (s).
How are derived physical quantities formed?
Derived physical quantities are formed by combining fundamental quantities, such as speed (distance/time), with units like meters per second (m/s).
How are dimensions used in equations?
Dimensions are used to test the homogeneity of an equation, ensuring that all terms in the equation have the same dimensional form.
What is an example of a derived physical quantity?
An example is density, which is mass per unit volume, with units of kilograms per cubic meter (kg/m³).
What are dimensions in physics?
Dimensions represent the physical nature of a quantity, such as [L] for length, [M] for mass, and [T] for time.
What factors affect the accuracy of measuring instruments?
The accuracy of measuring instruments can be affected by their precision, calibration, and the observer’s skill.
How do you estimate simple errors in measurements?
Simple errors can be estimated by considering the instrument’s smallest scale division and repeating measurements to find the range of values.
How do you express a measurement in standard form?
A measurement is expressed in standard form by writing it as a number between 1 and 10 multiplied by a power of 10, e.g., 3.2 × 10³.
